pippo

People,

I first posted on the General Forum, now I figured I should have posted here- sorry, Im new. Hopefully, moderator can delete first thread(?).

Anyway, trying to get some sot of step by step instructions/diagram for how to remove dash to access the AC evaporator. Mine leaks like crazy. Wondering if other memnbers here experienced this as well. I tried sucking out the ac drain tube with a vac, some fluid/water comes out, and help a bit, but within a week, evap floods again the passsenger floor. What a headache.

I never had a car that did this. How/why do these cobalts have this flaw? What else could be causing this back up/flooding? When I take a curve, you can hear the slusssssssshhhhhh/sloping nioise of a flooded evap case(?).

I have determined that the only way is to yank the entire dash, and open up this evap case, and figure it out that way. Its going to be a huge job.

Tips appreciated!

exninja

iTrader: (1)

I'd say either clean it out better ( straightened clothes hanger should do) or it's not the evaporator. Do you have a sunroof? Are you running the AC in December?

pippo

Yes, I am running ac in December. Its hot down here all year. No sunroof. I tried a wire, like a coat hanger, more supple though, to be able to make corners, but no luck. This drain problem defies all logic/mechanical ability. Thats why I believe no other way than to yank the dash board. Any diagrams/tutorial available that you know of ninja?

For your review, I have attached a bulletin from GM on the subject- seems this is a common problem, but they mention a white "plug" at drain, which is non existent in my car. Sheesh.

https://workshop-manuals.com/chevrol...er_carpet_wet/

Thanks!

exninja

iTrader: (1)

You can make a free account on AutoZone.com and use a repair guide for an earlier model year Cobalt. There should be no appreciable differences between years.

Kolt

I had the same issue on my ls thinking it was clogging but it actually wasn't. On mine the seal between the case and firewall has a crack on the bottom and when driving the water would stick to the bottom of the drain and drip back to the firewall, going by the seal and go into the floorboard. I used a 3 in long hose with a 90* bend, put it over the drain that way there is a neck for the water to run down so it doesn't go straight back to the firewall. No wet floor since. You should try that and see how it goes. Otherwise if the drain is stopping up your gonna need to cut a hole in the side of the case and use a airgun to push the trash out. I found on hhr's (why idk) its common for them to clog up with dust and make a clay like substance. With you in Florida you might have very fine silt in the case. Running a hanger in the drain would fix it for a little bit but it would come back. Started using a airgun through a hole in the case to blast the crap out. So far no comebacks.

pippo

Wow, good to know, Colt. Good, simple fix to place a 3" elbow extending the current drain pipe, as it is way too short. Any idea what then ID was on that tube extension?

So, the "side of the case", if I want to drill, do I access it by under the passenger foot area, right above the blower motor? other area? Seems like if I have to get to the SIDE, one has to position the drill from the side, where there is almost no gap for that. Not sure how you did that. Feedback appreciated!! I have gottten no other help ANYWHERE so far!!

Thanks.

Kolt

I don't remember what size hose I ended up using, just had some scrap hose laying around my bay at work.
Its hard to explain exactly where to drill, but it would be on the passenger side near the bottom. You would then use a mixture of hanger to break the trash up and a long neck blow gun to blow it out. If the hose deal doesn't work for you ill get a picture sometime of where you would need to make a hole. Have to be extra careful not to jam the bit in and puncture the heater core or evaporator. Youll need to plug the hole afterward of course, I use butyl weather sealant tape at work but I imagine gorilla tape would work almost as good.

pippo

Sounds like a plan. I will insert the tubing extension first, then see what happens. Could take a while, Kolt, as with the colder weather ac will not run as much. Anyway, will get back here to update you. Want to avoid the drilling method if possible.

pippo

I just had a thought hit my head- the water seepage/leakage gets onto the passenger floor eventually, but apparently seeps/oozes out front he evap case, as the case itself is inundated with water. It should not be drizzling down the drain tube in engine bay then backing up through firewall! Otherwise, I should have flooded floor and no waterlogged evap.

You see, even as I drive around, sometimes make a sharp turn, and whooooosh! Water sloshes out of the evap! You can even hear the water inside there sloshing around with no where to go. A while ago, I rigged up a flexible aluminum "pan", like what you would use to bake something then throw it out, under the evap case. That eventually fills up and overflows. So, Im betting the seepage does not come from engine bay backing up into passenger floor area. Make sense?

Still I have little to lose to install your extra length tubing.